Internet Protocol version 6 (IPv6) request for comments (RFC) 1883 (https://tools.ietf.org/html/rfc1883) came out in December 1995. That’s 22 years ago! So how do you connect to an IPv6 address without using a Domain Name Server (DNS)? It’s only slightly different than Internet Protocol version 4 (IPv4). You do need to make sure you have an IPv6 address before starting. If you are unsure that you have one, you can do an ipconfig (on Windows), ifconfig (on *nix), or download an app for you mobile device.
In IPv4, you can just type in the dotted decimal address into the Uniform Resource Locator (URL) address bar.
IPv6 does not use dotted decimal addresses though, it uses colon separated addresses that look like this: 2604:6000:1009:c2a2:6a05:caff:fe46:e2b5. The colon in the URL address bar actually serves a purpose. The left of the colon identifies the protocol to use. Common protocols used in the browser are http, https, and ftp. In order to use an IPv6 address without confusing the browser, you need to wrap the IPv6 address in square brackets.
This is also specified in RFC 2732 if you want to learn more. (http://www.ietf.org/rfc/rfc2732.txt)